1. Field of the Invention
The present invention relates to an inkjet ink composition and a method for producing the same, an inkjet recording method, a pigment dispersion and a method for producing the same.
2. Description of the Related Art
Inkjet systems ejecting an ink composition as droplets from ink ejection ports are widely used in many printers for reasons such as being compact and inexpensive, and enabling image forming on a recording medium without contact. Also among these inkjet systems, a piezo inkjet system using the deformation of a piezoelectric element to eject ink and a thermal inkjet system using a phenomenon of boiling of the ink composition by thermal energy to eject the ink composition as droplets have high resolution and excellent high-speed printing characteristics.
Here, over several years, there has been development of commercial printing and industrial printing using inkjet printers, without being limited to photo printing or document printing for domestic use or office use. In particular, the demand for wide-format inkjet printers suitable to printing large advertisements pasted in a show window or on the walls of a building, and the like, is expanding rapidly. Large advertisements are often used, mainly outside, and because long-term weather resistance is demanded, polyvinyl chloride and the like is widely used as the material, and an azo-based pigment having an azo skeleton (mainly used for yellow), a quinacridone-based pigment (mainly used for magenta), a copper phthalocyanine-based pigment (mainly used for cyan), and carbon black (mainly used for black) and the like, all having excellent weather resistance (resistance with respect to light, rain, or wind), are widely used as the pigment.
In addition, in order to perform full color printing, an inkjet ink set is used in which four colors, obtained by adding black ink to the three primary colors, yellow, magenta, and cyan, of ink in the subtractive color process, are combined.
For example, ink compositions disclosed in JP2004-2528A, WO2009/098509A, JP2012-72401A, JP2011-126881A, and JP2005-325279A are known as ink compositions. In addition, thermal transfer sheets disclosed in JP1997-272265A (JP-H09-272265A) are known of the related art.